Multi-speed rear drive for a bicycle

ABSTRACT

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 63/063,672, filed Aug. 10, 2020, which isincorporated herein by reference in its entirety for all purposes.

FIELD

Embodiments of the present invention relate to transmission for apedal-driven vehicle, such as a bicycle. In particular, embodimentsrelate to transmission for a multi-speed bicycle with a kickback gearhub.

BACKGROUND

Bicycling has increased in popularity recently, in part, due to anacknowledgment of its utility. Bicycles can be used for long andshort-range transportation and can provide a means for transportinggoods. A single bicycle can operate under many conditions and in variedenvironments as well. For example, multi-speed bicycles can be operatedon rough terrains as well as developed roads. These bicycles can includehub systems to facilitate speed shifting as needed between environments.

In the bicycle industry, hub systems can be expensive to produce and/orrepair. Transmission can require a handlebar-mounted shifter, which canbe difficult to maintain in rugged environments. Shifting cables can beused to connect the shifter to a rear derailleur and/or othertransmission means, however, these components can be easily damagedand/or contaminated. Further, transmission with kickback hubs can becomplex and/or inconvenient. For example, in multi-speed bicycles, akickback hub transmission can sequentially cycle through speeds insteadof directly activating a speed.

BRIEF SUMMARY

A multi-speed transmission for a bicycle wheel hub can include a driverto be arranged on a longitudinal axis of a bicycle wheel hub, aplurality of drive teeth arranged radially on the driver, and amulti-speed freewheel arranged on the longitudinal axis. The freewheelcan include a first sprocket to be connected to a first pedal drivesprocket via a first chain, a second sprocket to be connected to asecond pedal drive sprocket via a second chain, a plurality of pawlsradially arranged on the second sprocket to engage with the drive teethwhen the pedal shaft is rotated in the non-drive direction apredetermined rotation, a plurality of bias elements arranged radiallywithin an interior area of the second sprocket to bias the plurality ofpawls toward the drive teeth, and a shift ring arranged within aninterior area of the second sprocket to alternately block engagement ofthe pawls with the drive teeth.

A multi-speed transmission for a bicycle can include a driver having aplurality of drive teeth, a plurality of pawls radially arranged on thedriver, a first sprocket engaged with the plurality of pawls having afirst gear ratio, a second sprocket having a second gear ratio higherthan the first gear ratio, a plurality of pawls arranged radially on thesecond sprocket to drivingly engage the drive teeth of the driver aftermoving counterclockwise a predetermined rotation amount, a ring torotate with the first sprocket and extend within an interior area of thesecond sprocket, and a plurality of notches radially arranged on thering to engage with the pawls of the second sprocket and prevent thepawls of the second sprocket from engaging with the drive teeth to drivethe bicycle with the second sprocket. The bicycle can be driven with thesecond sprocket when the pawls of the second sprocket engage with thedrive teeth and the pawls of the first sprocket are overdriven. Thebicycle can be driven with the first sprocket when the second sprocketis prevented from engaging with the drive teeth of the driver.

A multi-speed transmission for a bicycle can include a first sprocketand a second sprocket configured to selectively transmit torque to awheel of a bicycle, a transmitting sprocket of the first sprocket andthe second sprocket can be shifted through pedaling in a non-drivedirection.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate embodiments and, together with thedescription, further serve to explain the principles of the embodimentsand to enable a person skilled in the relevant art(s) to make and usethe embodiments.

FIG. 1 is a side view of a multi-speed bicycle according to variousaspects of the invention.

FIG. 2 is a top view of a transmission according to various aspects ofthe invention.

FIG. 3 is an exploded view of a multi-speed freewheel according tovarious aspects of the invention.

FIG. 4 is a side view of the multi-speed freewheel of FIG. 3 arranged ona longitudinal axis from a second end according to various aspects ofthe invention.

FIG. 5 is a section view along 5-5 of the multi-speed freewheel in FIG.4 according to various aspects of the invention.

FIG. 6 is a section view along 7-7 of the multi-speed freewheel in FIG.4 according to various aspects of the invention.

FIG. 7 is a side view of the multi-speed freewheel of FIG. 3 arranged ona longitudinal axis from a second end according to various aspects ofthe invention.

FIG. 8 is a section view along 8-8 of the multi-speed freewheel in FIG.7 according to various aspects of the invention.

FIG. 9 is a rear view of the multi-speed freewheel of FIG. 3 arranged ona longitudinal axis at a first gear ratio according to various aspectsof the invention.

FIG. 10 is a section view along 10-10 of the multi-speed freewheel inFIG. 9 according to various aspects of the invention.

FIG. 11 is a section view along 11-11 of the multi-speed freewheel inFIG. 9 according to various aspects of the invention.

FIG. 12 is a section view along 12-12 of the multi-speed freewheel inFIG. 9 according to various aspects of the invention.

FIG. 13 is a rear view of the multi-speed freewheel of FIG. 3 arrangedon a longitudinal axis transitioning from drivingly engaging at a firstgear ratio to a second gear ratio according to various aspects of theinvention.

FIG. 14 is a section view along 14-14 of the multi-speed freewheel inFIG. 13 according to various aspects of the invention.

FIG. 15 is a rear view of the multi-speed freewheel of FIG. 3 arrangedon a longitudinal axis transitioning from drivingly engaging at a firstgear ratio to a second gear ratio according to various aspects of theinvention.

FIG. 16 is a section view along 16-16 of the multi-speed freewheel inFIG. 15 according to various aspects of the invention.

FIG. 17 is a section view along 17-17 of the multi-speed freewheel inFIG. 15 according to various aspects of the invention.

FIG. 18 is a rear view of the multi-speed freewheel of FIG. 3 arrangedon a longitudinal axis at a second gear ratio according to variousaspects of the invention.

FIG. 19 is a section view along 19-19 of the multi-speed freewheel inFIG. 18 according to various aspects of the invention.

FIG. 20 is a section view along 20-20 of the multi-speed freewheel inFIG. 18 according to various aspects of the invention.

FIG. 21 is a section view along 21-21 of the multi-speed freewheel inFIG. 18 according to various aspects of the invention.

FIG. 22 is a rear view of the multi-speed freewheel of FIG. 3 arrangedon a longitudinal axis transitioning from drivingly engaging at a secondgear ratio to a first gear ratio according to various aspects of theinvention.

FIG. 23 is a section view along 23-23 of the multi-speed freewheel inFIG. 22 according to various aspects of the invention.

FIG. 24 is a section view along 24-24 of the multi-speed freewheel inFIG. 22 according to various aspects of the invention.

FIG. 25 is a section view along 25-25 of the multi-speed freewheel inFIG. 22 according to various aspects of the invention.

Features and advantages of the embodiments will become more apparentfrom the detailed description set forth below when taken in conjunctionwith the drawings, in which like reference characters identifycorresponding elements throughout.

DETAILED DESCRIPTION

The present invention(s) will now be described in detail with referenceto embodiments thereof as illustrated in the accompanying drawings.References to “one embodiment”, “an embodiment”, “an exemplaryembodiment”, etc., indicate that the embodiment described may include aparticular feature, structure, or characteristic, but every embodimentmay not necessarily include the particular feature, structure, orcharacteristic. Moreover, such phrases are not necessarily referring tothe same embodiment. Further, when a particular feature, structure, orcharacteristic is described in connection with an embodiment, it issubmitted that it is within the knowledge of one skilled in the art toaffect such feature, structure, or characteristic in connection withother embodiments whether or not explicitly described.

Aspects of the present disclosure provide a multi-speed bicycle that canbe used on various surfaces, including rough and/or sloped terrain andpaved and unpaved roads. The bicycle can also be relatively straight inthe drive direction to assemble. Assembly can require easily sourcedparts/and or materials so that the design can be both accessible andinexpensive to produce. Additionally, the bicycle can be particularlyrobust such that maintenance needs are infrequent.

In some aspects, a multi-speed bicycle can include one or more sprocketsets to provide multiple gear ratios corresponding to, for example, alow gear ratio and a high gear ratio, respectively. These two gearratios can be suitable to traverse a wide variety of terrains. Asprocket set can include a pedal drive sprocket, a drive chain, and agear sprocket. Each sprocket set having a dedicated chain can be easy toassemble and maintain. A freewheel comprising the one or more sprocketsets can arrange the gear sprockets along a longitudinal axis of therear wheel hub. The gear sprockets can rotate freely about the rearwheel hub, or engage with a driver, also radially arranged along thelongitudinal axis of the rear wheel hub. The driver can have radiallyarranged drive teeth that can engage with the one or more gearsprockets. For example, driving the bicycle at a first gear ratio caninclude pawls associated with a first gear sprocket drivingly engagedwith the driver and drive teeth of the first gear sprocket to drive thebicycle at a first gear ratio. A second gear sprocket can provide asecond gear ratio such that pawls associated with the second gearsprocket drivingly engage with the drive teeth of the driver to drivethe bicycle at a second gear ratio. Driving engagement can transmittorque from the gear sprocket to the bicycle wheel.

In some aspects, a transmission comprising the one or more sprocket setscan be easily toggled to shift between the respective gear ratios.Instead of requiring a handlebar-mounted shifter and shifting cables,the transmission can be toggled, for example, by rotating transmissioncomponents, e.g., the pedal shaft and the corresponding sprocket setcomponents, in the non-drive direction. In an aspect, the transmissioncan be toggled when transmission components are rotated in the non-drivedirection a rotational amount required to transition from the first gearsprocket being drivingly engaged with the driver to a second gearsprocket being drivingly engaged with the driver.

A shift ring (e.g., a transmitting sprocket) can be arranged along thelongitudinal axis to facilitate the transition and selectively transmittorque to the bicycle wheel. The shift ring can extend into portions ofthe interior of the second gear sprocket. As the pedal shaft is rotatedin the non-drive direction the rotational amount required to transitionfrom drivingly engaging the first gear sprocket at a first gear ratio todrivingly engaging the second gear sprocket at a second gear ratio, thefreewheel can rotate about the longitudinal axis, allowing the pawls ofthe second gear sprocket to engage with the drive teeth of the driver.As the pedal shaft is rotated in the drive direction, the pawls of thesecond gear sprocket are drivingly engaged with the drive teeth of thedriver such that the second gear sprocket is drivingly engaged and thebicycle is driven at a second gear ratio. At other rotations where theshift ring is extended into the interior of the second gear sprocket,the shift ring can block the pawls of the second gear sprocket fromengaging with the drive teeth of the driver. Instead, the pawls of thesecond gear sprocket can engage with the shift ring at the locationswhere the shift ring is extended into the interior of the second gearsprocket. As the pedal shaft is rotated in the drive direction, thepawls associated with the first sprocket are drivingly engaged with thedriver and drive teeth of the first gear sprocket to drive the bicycleat a first gear ratio.

Aspects of the present disclosure will now be described in more detailwith reference to the figures. A multi-speed bicycle 100 is shown inFIG. 1. In some aspects, bicycle 100 can include a front wheel 102, arear wheel 104, a frame 106, a rack member 109, a rear wheel hub 200,and/or a multi-speed freewheel 206.

Frame 106 can support front wheel 102 and/or rear wheel 104. Rear wheelhub 200 can be positioned on the rear axle of bicycle 100 such that itcan be rotationally supported by the rear axle. Rear wheel hub 200 canbe operatively connected to the spokes and annular rim of rear wheel104. Multi-speed freewheel 206 can be mounted onto rear wheel hub 200and can rotate freely about the rear axle.

A rack member 109 can be removably attached to frame 106. Rack member109 can include a plurality of members connected to frame 106 and can beexpandable to hold and transport a variety of goods. For example, rackmember 109 can include a surface on which goods can be placed.Additional surfaces can be attached to increase the area on which goodscan be placed.

In some aspects, components of bicycle 100 can be easily sourced (e.g.,locally or regionally), which can minimize assembly costs. Greateraccess to parts can facilitate home or local repairs, which can alsoincrease access to maintenance and minimize repair costs. This can beespecially important in remote locations. Additionally, materials usedcan be such that repairs are infrequently needed. In an aspect, some orall of the components of frame 106 can be made of or reinforced bymaterials to provide durability (e.g., strength, stability, resilience,rust deterrence). In an aspect, frame 106 can comprise metal, plastic,or a composite material, and/or combinations thereof, including, forexample, steel, aluminum, titanium, carbon fiber, plastic, bamboo, etc.Frame 106 can be particularly strong to allow support and transmissionof large loads. Additionally, some or all of the components of frame 106can be modular and reusable such that the components can be assembledinto a second bicycle 100 or another device.

Referring now to FIGS. 1-2, in some aspects, a transmission for bicycle100 can include a pedal shaft hub 110, a first pedal 112, a second pedal114, a pedal shaft 116, a first pedal drive sprocket 118, a second pedaldrive sprocket 120, a rear wheel hub 200, a first chain 202, a secondchain 204, multi-speed freewheel 206, a first sprocket 220, and secondsprocket 234. First pedal 112 and second pedal 114 can be used to rotatepedal shaft 116.

Transmission components can interact with one another to provide driving(i.e., motive) force. In some aspects, transmission components providedriving force in one direction. In an aspect, rotating pedal shaft 116in the drive direction (e.g., the direction that provides driving force)can be a clockwise rotation when viewing, e.g., FIGS. 1-2. In an aspect,rotating pedal shaft 116 in a non-drive direction (e.g., a directionthat does not provide driving force) can be a counterclockwise rotationwhen viewing, e.g., FIGS. 1-2.

With reference to FIG. 2, transmission components can interact with oneother to provide driving force. In an aspect, rotating pedal shaft 116in the drive direction can rotate the transmission components, e.g.,first pedal drive sprocket 118, first chain 202, first sprocket 220,second pedal drive sprocket 120, second chain 204, and second sprocket234, in the drive direction. The transmission components can providedifferent gear ratios to move rear wheel 104 and propel bicycle 100 inthe drive direction. For example, driving force can be provided at afirst gear ratio by first sprocket 220 being drivingly engaged with adriver connected to rear wheel 104. Driving force can be provided at asecond gear ratio by second sprocket 234 being drivingly engaged with adriver connected to rear wheel 104. When not drivingly engaged, a gearsprocket can be engaged such that it touches but does not providedriving force and can rotate with the transmission components.

In some aspects, rotating pedal shaft 116 in the non-drive direction canrotate the transmission components, e.g., first pedal drive sprocket118, first chain 202, first sprocket 220, second pedal drive sprocket120, second chain 204, and second sprocket 234, in the non-drivedirection. The transmission can be toggled, for example, by rotatingpedal shaft 116 in the non-drive direction a rotational amount requiredto transition from first sprocket 220 being drivingly engaged withdriver 208 to second sprocket 234 being drivingly engaged with driver208 once pedal shaft 116 and transmission components are rotated in thedrive direction.

The first gear ratio can be provided by first sprocket 220, first pedaldrive sprocket 118, and first chain 202. The second gear ratio can beprovided by second sprocket 234, second pedal drive sprocket 120, andsecond chain 204. The gear ratio can be determined by the number ofteeth of the engaged pedal drive sprocket and the number of teeth of thedrivingly engaged gear sprocket. In some aspects, first pedal drivesprocket 118 and second pedal drive sprocket 120 can include a pluralityof gear teeth. In an aspect, first pedal drive sprocket 118 can includethe same number of gear teeth as second pedal drive sprocket 120. Inanother aspect, first pedal drive sprocket 118 can include a differentnumber of gear teeth than second pedal drive sprocket 120. For example,second pedal drive sprocket 120 can include more gear teeth than firstpedal drive sprocket 118. In an aspect, first pedal drive sprocket 118can include approximately 27 gear teeth and second pedal drive sprocket120 can include approximately 44 gear teeth.

As shown in FIG. 2, bicycle 100 can include one or more pedal drivesprockets operatively connected to one or more gear sprockets of afreewheel arranged on the longitudinal axis 201 of rear wheel hub 200(e.g., first sprocket 220 or second sprocket 234). In an aspect, firstpedal drive sprocket 118 can drive first sprocket 220 using first chain202 and second pedal drive sprocket 120 can drive second sprocket 234using second chain 204.

In some aspects, first sprocket 220 can be directly driven by firstchain 202 that can encircle first sprocket 220 and first pedal drivesprocket 118. Similarly, second sprocket 234 can be directly driven bysecond chain 204 that can encircle second sprocket 234 and second pedaldrive sprocket 120. In some aspects, first chain 202 and/or second chain204 can be surrounded by a cage or cover to protect first sprocket 220,first pedal drive sprocket 118, second sprocket 234, and/or second pedaldrive sprocket 120. In some aspects, the cage can surround all or partof first sprocket 220, first pedal drive sprocket 118, second sprocket234, and/or second pedal drive sprocket 120 as well. First chain 202and/or second chain 204 can be arranged such that they can engage withonly one sprocket set (i.e., the chains do not move between sprockets).In this way, each sprocket set (first sprocket 220 and first pedal drivesprocket 118, and second sprocket 234 and second pedal drive sprocket120) can have a dedicated chain, which can create dedicatedgear-shifting for multi-speed transmission. First chain 202 and secondchain 204 can run generally parallel to each other from first pedaldrive sprocket 118 and second pedal drive sprocket 120 to first sprocket220 and second sprocket 234, respectively.

Pedal shaft 116 can be cylindrically shaped and can be arranged along alongitudinal axis 117 of pedal shaft hub 110. In an aspect, pedal shaft116 can support first pedal 112 and second pedal 114. In some aspects,bicycle 100 can include one or more pedal drive sprockets. For example,a first pedal drive sprocket 118 and a second pedal drive sprocket 120can be mounted onto pedal shaft 116 and/or arranged on one side of pedalshaft hub 110 along the longitudinal axis 117 (e.g., the left side orthe right side when viewing FIG. 2 from the top). First pedal drivesprocket 118 and second pedal drive sprocket 120 can be axially arrangedin close relation on pedal shaft 116. In an aspect, first pedal drivesprocket 118 can be arranged adjacent to pedal shaft hub 110 on pedalshaft 116. In an aspect second pedal drive sprocket 120 can bepositioned adjacent and outside first pedal drive sprocket 118 alonglongitudinal axis 117 of pedal shaft 116.

In some aspects, multi-speed freewheel 206 can be arranged along alongitudinal axis 201 of rear wheel hub 200. First sprocket 220 andsecond sprocket 234 can be axially arranged in close relation to rearwheel hub 200 and can be aligned with first pedal drive sprocket 118 andsecond pedal drive sprocket 120, respectively.

As shown in FIG. 3, multi-speed freewheel 206 can include driver 208,seal 212, bearing 214, first pawl bias member 216, first sprocket 220,friction element 222, shift ring 224 (e.g., a transmitting sprocket),extended surface 226 of shift ring 224, a bearing 230, a seal 232,second sprocket 234, a second pawl bias member 238, a bearing 240, abearing shim 242, bearing cap 244, and/or a shield 246. Driver 208 caninclude a plurality of teeth 250 (e.g., drive teeth), groove 209 (e.g.,a drive groove), and a removal tool interface 210. Pawl bias member 216can include one or more of a pawl 218 (e.g., first gear ratio engagingpawl) and a pawl 219 (e.g., first gear ratio engaging pawl). Firstsprocket 220 can include a plurality of teeth 248 (e.g., drive teeth).Shift ring 224 can include extended surface 226 having one or morenotches 228 and an end 229. Second pawl bias member 238 can include oneor more of a pawl 236 (e.g., second gear ratio engaging pawl) and a pawl237 (e.g., second gear ratio engaging pawl).

Driving force can be provided by one of first sprocket 220 or secondsprocket 234 drivingly engaging with driver 208. Driving engagement cantransmit torque from, e.g., first sprocket 220 or second sprocket 234,to rear wheel 104. Multi-speed freewheel 206 components can interactwith one or more gear sprockets to provide the driving engagement anddriving force. In an aspect, driving force can be provided at a firstgear ratio by first sprocket 220 being drivingly engaged with driver208. The torque can be transmitted from first sprocket 220 to driver 208by teeth 248. In this aspect, pawl 218 and/or pawl 219 can be drivinglyengaged with teeth 248 of first sprocket 220 and one of groove recesses209 a, 209 b, respectively. Alternatively, driving force can be providedat a second gear ratio by second sprocket 234 being drivingly engagedwith teeth 250 of driver 208. In this aspect, pawl 236 and/or pawl 237can be drivingly engaged to teeth 250 of driver 208 and end 229 ofextended surface 226. The torque can be transmitted from second sprocket234 to driver 208 by teeth 250.

Rotating pedal shaft 116 can rotate the transmission components andmulti-speed freewheel 206 components. When not drivingly engaged toprovide driving force to rear wheel 104, multi-speed freewheel 206components can be drivingly engaged to other components. For example,when first sprocket 220 is drivingly engaged to driver 208, secondsprocket 234 can be drivingly engaged to shift ring 224 such that itdoes not provide driving force to driver 208 but can rotate with shiftring 224 at the second gear ratio. Similarly, multi-speed freewheel 206components can be engaged, but not drivingly engaged to rear wheel 104or a component of multi-speed freewheel 206. For example, when secondsprocket 234 is drivingly engaged to driver 208, first sprocket 220 canbe engaged, but not drivingly engaged, to driver 208 such that firstsprocket 220 can rotate in the drive direction at the first gear ratio.In this aspect, first sprocket 220 does not provide the driving force todriver 208 because the rotation of first sprocket 220 at the first gearratio is slower than rotation of second sprocket 234 at the second gearratio. Other components of multi-speed freewheel 206 can be touching,but not drivingly engaged or engaged.

In some aspects, driver 208 can be removably coupled to rear wheel hub200, for example by a threaded connection. Driver 208 can be arranged onits central axis along the longitudinal axis 201 of rear wheel hub 200.In an aspect, first sprocket 220 and second sprocket 234 can bepositioned about driver 208 such that driver 208 can directly supportfirst sprocket 220 and indirectly support second sprocket 234 (e.g.,through bearing 230, bearing 240, and/or bearing shim 242). Groove 209and teeth 250 can be radially arranged on driver 208 such that groove209 is axially spaced from teeth 250.

In some aspects, seal 212, bearing 214, first pawl bias member 216, pawl218, and pawl 219 can be arranged along the longitudinal axis 201 ofrear wheel hub 200 such that seal 212, bearing 214, first pawl biasmember 216, pawl 218, and pawl 219 can be positioned about the portionof driver 208 within an interior area of first sprocket 220. In anaspect, first pawl bias member 216 can be positioned within groove 209and at least one of pawl 218 and pawl 219 can be positioned in grooverecesses 209 a, 209 b, respectively. At least one of pawl 218 and pawl219 can engage one or more of teeth 248 of first sprocket 220 to engageand/or drivingly engage driver 208.

Shift ring 224 can include extended surface 226 having end 229 andnotches 228 to selectively transmit torque from multi-speed freewheel206 to rear wheel 104. Extended surface 226 can be positioned within aninterior area of second sprocket 234. Since shift ring 224 can bepositioned about driver 208, it can also be positioned about teeth 250of driver 208.

In some aspects, second pawl bias member 238, pawl 236, pawl 237,bearing 240, and seal 232 can be arranged along longitudinal axis 201 ofrear wheel hub 200 such that second pawl bias member 238, pawl 236, pawl237, bearing 240, and seal 232 can be positioned about a portion ofdriver 208 within an interior area of second sprocket 234.

In some aspects, friction element 222 and shift ring 224 can be arrangedalong the longitudinal axis 201 of rear wheel hub 200. Friction element222 and shift ring 224 can be positioned about the portion of driver 208within an interior area of first sprocket 220. In some aspects, frictionelement 222 and shift ring 224 can be radially aligned such thatfriction element 222 can be positioned in an outer edge of shift ring224. Shift ring 224 and friction element 222 can be positioned about theportion of driver 208 having a portion within an interior area of firstsprocket 220. In an aspect, shift ring 224 and friction element 222 canbe drivingly engaged to first sprocket 220 such that shift ring 224 andfriction element 222 are coupled to first sprocket 220. In this aspect,second sprocket 234 can rotate in the non-drive direction relative toshift ring 224 and engage with teeth 250 of driver 208 and end 229 ofextended surface 226. In this aspect, when pedal shaft 116 and thetransmission components are rotated in the drive direction, pawl 236and/or pawl 237 can be drivingly engaged with teeth 250 and end 229 suchthat second sprocket 234 can drivingly engage with driver 208 (i.e.,torque is transmitted from second sprocket 234 to driver 208) to driverear wheel 104 and propel bicycle 100 in the drive direction.

In another aspect, shift ring 224 and friction element 222 can beengaged to first sprocket 220 such that shift ring 224 and frictionelement 222 are not coupled to first sprocket 220. In some aspects, whenpedal shaft 116 and the transmission components are rotated in the drivedirection, pawl 236 and pawl 237 cannot be drivingly engaged with teeth250 and end 229 and second sprocket 234 cannot drivingly engage withdriver 208 to move rear wheel 104 and propel bicycle 100 in the drivedirection. In this aspect, pawl 218 and/or pawl 219 can be drivinglyengaged with teeth 248 such that driver 208 is drivingly engaged tofirst sprocket 220 (i.e., torque is transmitted from first sprocket 220to driver 208) and rear wheel 104 can be moved and bicycle 100 can bepropelled in the drive direction at the first gear ratio.

In some aspects, bearing cap 244 can be removably secured to driver 208(e.g., bearing cap 244 can thread onto driver) to cover the respectivecomponents of multi-speed freewheel 206. Bearing shim 242 can bepositioned about driver 208 and axially closer to first sprocket 220than bearing cap 244. In an aspect, bearing shim 242 can be axiallycloser to bearing cap 244 than to first sprocket 220. In an aspect,bearing shim 242 can secure bearing cap 244 and apply a set oradjustable preload (e.g., axially or radially) to one or more bearingsarranged over driver 208. In some aspects, multi-speed freewheel 206 caninclude one or more bearing shims 242. In some aspects, shield 246 canbe removably arranged partially or entirely over multi-speed freewheel206.

With reference to FIGS. 4-6, rotating pedal shaft 116 in the drivedirection rotates sprockets 118/120 and chains 202/204 and in turn firstsprocket 220 and second sprocket 234 to provide the driving force forbicycle 100. In some aspects, when pedal shaft 116 is rotated in thenon-drive direction, multi-speed freewheel 206 can disengage from rearwheel hub 200. First sprocket 220 or second sprocket 234 can freelyrotate about the central axis of driver 208. The transmission can betoggled when pedal shaft 116 and the transmission components are rotatedin the non-drive direction a rotational amount required to transitionfrom a first gear being drivingly engaged with driver 208 to a secondgear being drivingly engaged with driver 208 (e.g., one-quarterrotation). Since multi-speed freewheel 206 can disengage from rear wheelhub 200 when pedal shaft 116 is rotated in the non-drive direction, thedriving force from the pedal drive sprockets to the gear sprockets (bythe drive chains) is transferred in only one direction.

In an aspect, friction element 222 can be positioned in an outer edge ofshift ring 224 such that they are coupled together. In this aspect,rotation can be locked between friction element 222 and shift ring 224.In some aspects, the arrangement of bearing shim 242 can enable driver208 to support the free rotation of first sprocket 220 and/or secondsprocket 234 about the central axis of driver 208.

In an aspect, at least one of pawl 218 and pawl 219 can be engaged withteeth 248, which can be radially arranged within an interior area offirst sprocket 220. In an aspect, bearing 214 can provide rotationalsupport to first sprocket 220 and can be sealed. For example, seal 212can be provided to retain lubricant in bearing 214 and/or preventexternal contamination of bearing 214 and/or other components ofmulti-speed freewheel 206. In an aspect, bearing 214 can be a rollerbearing (e.g., tapered, cylindrical, or needle) that can enable driver208 to support the free rotation of first sprocket 220 aboutlongitudinal axis 201 and resolve any remaining system forces.

In an aspect, at least one of pawl 236 and pawl 237 can be positionedwithin an interior area of second sprocket 234. Second pawl bias member238 and at least one of pawl 236 and pawl 237 can be positioned aroundteeth 250 of driver 208. In an aspect, bearing 240 can providerotational support to second sprocket 234. In an aspect, bearing 240 canbe a roller bearing (e.g., tapered, cylindrical, or needle) that canenable driver 208 to support the free rotation of second sprocket 234about the central axis of driver 208 and resolve any remaining systemforces. In some aspects, removal tool interface 210 can be compatiblewith industry standard tools (e.g., Park Tool FR-4) and can be used toremove multi-speed freewheel 206 from rear wheel hub 200. In an aspect,shield 246 can be provided to retain lubricant in bearing 240 and/orprevent external contamination of bearing 240 and/or other components ofmulti-speed freewheel 206. In other aspects, shield 246 can protect allor part of multi-speed freewheel 206 from environmental impacts that canaggravate maintenance needs (e.g., rain, wind, dust, etc.).

Shift ring 224 can be arranged along longitudinal axis 201 to facilitatetransition from a first gear ratio where first sprocket 220 is drivinglyengaged with driver 208 to a second gear ratio where second sprocket 234is drivingly engaged with driver 208 as pedal shaft 116 and thetransmission components are rotated in the drive direction. Extendedsurface 226 of shift ring 224 can be positioned within an interior areaof second sprocket 234 between at least one of pawl 236 and pawl 237. Aspedal shaft 116 and the transmission components are rotated in thenon-drive direction, multi-speed freewheel 206 can rotate about thelongitudinal axis 201. In this aspect, shift ring 224 and frictionelement 222 can be drivingly engaged to first sprocket 220. Secondsprocket 234 can then rotate relative to shift ring 224. As pedal shaft116 and the transmission components are rotated in the non-drivedirection the amount required to transition from the first gear ratio tothe second gear ratio (e.g., one-quarter rotation), pawl 236 and/or pawl237 (i.e., at least one gear pawl on second pawl bias member 238) canengage with teeth 250 of driver 208 and end 229 of extended surface 226.When pedal shaft 116 and the transmission components are rotated in thedrive direction, pawl 236 and/or pawl 237 can be drivingly engaged withteeth 250 and end 229 such that rear wheel 104 can be moved and bicycle100 can be propelled in the drive direction at the second gear ratio.

In this aspect, because first sprocket 220 can provide a first gearratio at which rotation of first sprocket 220 is slower than rotation ofsecond sprocket 234, pawl 218 and pawl 219 can be engaged with teeth 248of first sprocket 220 but not drivingly engaged when pedal shaft 116 andthe transmission components are rotated in the drive direction. Firstsprocket 220 does not provide the driving force to propel bicycle 100because the second sprocket 234 is drivingly engaged at a higher gearratio with a faster rotation. Because of the faster rotation at thesecond gear ratio, at least one of pawl 218 and pawl 219 are overdriven.In this aspect, at least one of pawl 218 and pawl 219 can pivot ingroove recesses 209 a, 209 b, respectively, and be overdriven. Thisarrangement can maintain the axial alignment of first sprocket 220 whilemoving rear wheel 104 at the second gear ratio.

In other aspects, as pedal shaft 116 and the transmission components arerotated in the non-drive direction, the rotation might not provide fortransitioning from the first gear ratio to the second gear ratio. Inthis aspect, the second gear ratio is not triggered. Instead, extendedsurface 226 of shift ring 224 blocks the engagement between pawl 236and/or pawl 237 with teeth 250 and end 229 of extended surface 226. As aresult, when pedal shaft 116 and the transmission components are rotatedin the drive direction, pawl 236 and pawl 237 cannot be drivinglyengaged with teeth 250 and end 229 and second sprocket 234 cannotdrivingly engage with driver 208 to move rear wheel 104 and propelbicycle 100 in the drive direction. Instead, pawl 236 and/or pawl 237can be drivingly engaged with notches 228, not driver 208, and shiftring 224 can rotate in the drive direction with second sprocket 234 atthe second gear ratio. In this aspect, pawl 218 and/or pawl 219 can bedrivingly engaged with teeth 248 such that driver 208 is drivinglyengaged to first sprocket 220 and rear wheel 104 can be moved andbicycle 100 can be propelled in the drive direction at the first gearratio.

In some aspects, as shown in FIGS. 7-8, first sprocket 220 diameter, D1,can be smaller than second sprocket 234 diameter, D2 and as such, canhave a different number of teeth. In an aspect, second sprocket 234rotates faster than first sprocket 220 because of a higher gear ratiobased at least in part on the relative sizes of D1 and D2.

In some aspects, first chain 202 and second chain 204 can differ in sizeto provide the different gear ratios. Chain and/or sprocket sizes can beselected such that both first chain 202 and second chain 204 can besimultaneously tensioned. Alternatively, commonly known chain tensionerscan be used to tension first chain 202 and/or second chain 204.

With reference to FIGS. 9-12, in some aspects, rear wheel 104 can bemoved and bicycle 100 can be propelled in the drive direction at thefirst gear ratio. At the first gear ratio, at least one of pawl 218 andpawl 219 can be drivingly engaged with one or more of teeth 248 of firstsprocket 220 to move rear wheel 104 and propel bicycle 100 in the drivedirection. As shown in FIG. 10, in an aspect, teeth 248 of firstsprocket 220 can be radially arranged on first sprocket 220. At leastone of pawl 218 and pawl 219 positioned in groove recesses 209 a, 209 bon driver 208 can be engaged with first pawl bias member 216, which canbias pawl 218 and pawl 219 (e.g., concurrently or separately) toward oneor more teeth 248 of first sprocket 220 (e.g., via metal springs,elastomeric material, etc.). At least one of pawl 218 and pawl 219 canengage with teeth 248 such that driver 208 is engaged to first sprocket220. When pedal shaft 116 and the transmission components are rotated inthe drive direction, pawl 218 and/or pawl 219 can be drivingly engagedwith teeth 248 such that driver 208 is drivingly engaged to firstsprocket 220. In this aspect, rear wheel 104 can be moved and bicycle100 can be propelled in the drive direction at the first gear ratio. Inan aspect, at least one of pawl 218 and pawl 219 can pivot in grooverecesses 209 a, 209 b, respectively, such that it can be a free-ridingpawl and can axially support first sprocket 220. In this aspect, atleast one of pawl 218 and pawl 219 can be active in that rear wheel 104can be moved and bicycle 100 can be propelled in the drive direction atthe first gear ratio.

As shown in FIG. 11, at least one of pawl 236 and pawl 237 can beradially arranged within second sprocket 234. At least one of pawl 236and pawl 237 can be engaged with second pawl bias member 238, which canbias pawl 236 and pawl 237 (e.g., concurrently or separately) toward oneor more teeth 250 of driver 208 (e.g., via metal springs, elastomericmaterial, etc.). At the second gear ratio, at least one of pawl 236 andpawl 237 can be biased toward teeth 250 such that second sprocket 234can be engaged with teeth 250 of driver 208 and end 229 of extendedsurface 226. When in the first gear ratio, pawl 236 and pawl 237 cannotengage with teeth 250 and end 229 of extended surface 226. As a result,when pedal shaft 116 and the transmission components are rotated in thedrive direction, pawl 236 and pawl 237 cannot be drivingly engaged withteeth 250 and end 229 and second sprocket 234 cannot drivingly engagewith driver 208 to move rear wheel 104 and propel bicycle 100 in thedrive direction. In this aspect, pawl 218 and/or pawl 219 can bedrivingly engaged with teeth 248 such that driver 208 is drivinglyengaged to first sprocket 220 and rear wheel 104 can be moved andbicycle 100 can be propelled in the drive direction at the first gearratio. In this aspect, at least one of pawl 236 and pawl 237 can insteadbe engaged with notches 228 of shift ring 224 such that at least one ofpawl 236 and pawl 237 can be drivingly engaged with shift ring 224. Atthe first gear ratio, at least one of pawl 236 and pawl 237 can driveshift ring 224 in the drive direction at the second gear ratio providedby second sprocket 234 (at the speed of the second sprocket 234) and canbe inactive (i.e., prevented from drivingly engaging with driver 208).

As shown in FIG. 12, rotating pedal shaft 116 and the transmissioncomponents in the drive direction can cause rotation in the drivedirection of shift ring 224 since at least one of pawl 236 and pawl 237can drivingly engage with shift ring 224 by notches 228. The rotation inthe drive direction of shift ring 224 can decrease the diameter, D3, offriction element 222, reducing the friction forces and decoupling shiftring 224 and friction element 222 from first sprocket 220.

With reference to FIGS. 13-17, multi-speed freewheel 206 can transitionfrom the first gear ratio with first sprocket 220 drivingly engaged withdriver 208 to the second gear ratio with second sprocket 234 drivinglyengaged with driver 208. In some aspects, as pedal shaft 116 and thetransmission components are rotated in the non-drive direction,multi-speed freewheel 206 can transition the first gear ratio to thesecond gear ratio. In some aspects, as pedal shaft 116 and thetransmission components are rotated in the non-drive direction, at leastone of pawl 236 and pawl 237 of second sprocket 234 can continuallyengage and disengage notches 228 of shift ring 224, end 229 of extendedsurface 226, and teeth 250 of driver 208. Accordingly, the transmissioncan continually be toggled between the first gear ratio and the secondgear ratio.

As shown in FIG. 17, rotating pedal shaft 116 and the transmissioncomponents in the non-drive direction can cause the rotation in thenon-drive direction of shift ring 224 because shift ring 224 can becoupled to first sprocket 220. The rotation in the non-drive directionof shift ring 224 can increase the diameter, D3, of friction element222, increasing the friction forces and coupling shift ring 224 andfriction element 222 to first sprocket 220.

Pawl 236 and pawl 237 rotates in the non-drive direction at the secondgear ratio faster than shift ring 224 coupled to first sprocket 220,which rotates at the first gear ratio. This can cause pawl 236 and pawl237 to rotate relative to shift ring 224. As a result, pawl 236 and/orpawl 237 can advance away from notches 228 and extended surface 226. Atleast one of pawl 236 and pawl 237 can be engaged with second pawl biasmember 238, which can bias pawl 236 and pawl 237 (e.g., concurrently orseparately) toward one or more teeth 250 (e.g., via metal springs,elastomeric material, etc.). At a predetermined rotation, at least oneof pawl 236 and pawl 237 can be biased toward teeth 250 of driver 208and can engage with teeth 250 and end 229 of extended surface 226 onshift ring 224. In this aspect, when pedal shaft 116 and thetransmission components are rotated in the drive direction, pawl 236and/or pawl 237 can be drivingly engaged with teeth 250 and end 229 suchthat second sprocket 234 can drivingly engage with driver 208 to driverear wheel 104 and propel bicycle 100 in the drive direction at thesecond gear ratio.

With reference to FIGS. 18-21, in some aspects, bicycle 100 can propelin the drive direction at the second gear ratio. At least one of thepawl 236 and pawl 237 can be active at the second gear ratio, such thatat least one of pawl 236 and pawl 237 can drive rear wheel 104 andpropel bicycle 100 in the drive direction. As shown in FIG. 19, in anaspect, at least one of pawl 236 and pawl 237 can drivingly engage withteeth 250 of driver 208 and end 229 of extended surface 226 at thesecond gear ratio.

As shown in FIG. 20, in some aspects, at the second gear ratio, at leastone of pawl 218 and pawl 219 can be engaged, but not drivingly engaged,with teeth 248 of first sprocket 220. In the second gear ratio, at leastone of pawl 236 and pawl 237 can be drivingly engaged with teeth 250 andend 229 of extended surface 226 and the second sprocket 234 can moverear wheel 104 and propel bicycle 100 in the drive direction. Becausethe second sprocket 234 is drivingly engaged with driver 208 at a highergear ratio with a faster rotation than first sprocket 220, pawl 218and/or pawl 219 are overdriven into groove recesses 209 a, 209 b suchthat pawl 218 and pawl 219 can be engaged with teeth 248 but notdrivingly engaged to provide the driving force to move rear wheel 104and propel bicycle 100.

As shown in FIG. 21, rotating pedal shaft 116 and the transmissioncomponents in the drive direction can cause the rotation in the drivedirection of shift ring 224 because at least one of pawl 236 and pawl237 can drivingly engage with teeth 250 and end 229 of extended surface226. The rotation in the drive direction of shift ring 224 can decreasethe diameter, D3, of friction element 222, reducing the friction forcesand decoupling shift ring 224 from first sprocket 220.

With reference to FIGS. 22-25, multi-speed freewheel 206 can transitionfrom the second gear ratio to the first gear ratio. With reference toFIGS. 22-23, in some aspects, as pedal shaft 116 are rotated in thenon-drive direction, at least one of pawl 236 and pawl 237 of secondsprocket 234 can continually engage notches 228 of shift ring 224, end229 of extended surface 226, and teeth 250 of driver 208. Accordingly,the transmission can continually be toggled between the first gear ratioand the second gear ratio. As shown in FIG. 24, at least one of pawl 218and pawl 219 located on driver 208 can remain engaged with teeth 248 offirst sprocket 220.

As shown in FIG. 25, rotating pedal shaft 116 and the transmissioncomponents in the non-drive direction can cause the rotation in thenon-drive direction of shift ring 224 because shift ring 224 can becoupled to first sprocket 220. The rotation in the non-drive directionof shift ring 224 can increase the diameter, D3, of friction element222, increasing the friction forces and coupling shift ring 224 andfriction element 222 to first sprocket 220.

Pawl 236 and pawl 237 rotates in the non-drive direction at the secondgear ratio faster than shift ring 224 coupled to first sprocket 220,which rotates at the first gear ratio. This can cause pawl 236 and pawl237 to rotate relative to shift ring 224. As a result, pawl 236 and/orpawl 237 can advance away from notches 228 and extended surface 226 ofshift ring 224. In an aspect, the non-drive direction rotation does notreach a predetermined rotation such that at least one of pawl 236 andpawl 237 can be biased toward teeth 250 of driver 208 and can engagewith teeth 250 and end 229 of extended surface 226 of shift ring 224. Asa result, when pedal shaft 116 and the transmission components arerotated in the drive direction, pawl 236 and pawl 237 cannot bedrivingly engaged with teeth 250 and end 229 and second sprocket 234cannot drivingly engage with driver 208 to move rear wheel 104 andpropel bicycle 100 in the drive direction. In this aspect, pawl 218and/or pawl 219 can be drivingly engaged with teeth 248 such that driver208 is drivingly engaged to first sprocket 220 and rear wheel 104 can bemoved and bicycle 100 can be propelled in the drive direction at thefirst gear ratio. At least one of pawl 236 and pawl 237 can be engagedwith notches 228 of shift ring 224 such that at least one of pawl 236and pawl 237 can be drivingly engaged with shift ring 224. In thisaspect, shift ring 224 can rotate in the drive direction at the secondgear ratio provided by second sprocket 234. In this configuration, thepawl 236 and pawl 237 can be inactive (i.e., prevented from drivinglyengaging with teeth 250 of driver 208 and end 229 of extended surface226).

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or morebut not all exemplary embodiments of the present invention(s) ascontemplated by the inventor(s), and thus, are not intended to limit thepresent invention(s) and the appended claims in any way.

The present invention(s) have been described above with the aid offunctional building blocks illustrating the implementation of specifiedfunctions and relationships thereof. The boundaries of these functionalbuilding blocks have been arbitrarily defined herein for the convenienceof the description. Alternate boundaries can be defined so long as thespecified functions and relationships thereof are appropriatelyperformed. The foregoing description of the specific embodiments will sofully reveal the general nature of the invention(s) that others can, byapplying knowledge within the skill of the art, readily modify and/oradapt for various applications such specific embodiments, without undueexperimentation, without departing from the general concept of thepresent invention(s). Therefore, such adaptations and modifications areintended to be within the meaning and range of equivalents of thedisclosed embodiments, based on the teaching and guidance presentedherein. It is to be understood that the phraseology or terminologyherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance. The breadth and scope of the present invention(s) should notbe limited by any of the above-described exemplary embodiments, butshould be defined only in accordance with the following claims and theirequivalents.

What is claimed is:
 1. A multi-speed transmission for a bicycle wheelhub, comprising: a driver to be arranged on a longitudinal axis of thebicycle wheel hub, the driver including a groove and a plurality ofdrive teeth; and a multi-speed freewheel arranged on the longitudinalaxis of the bicycle wheel hub, the freewheel comprising: a firstsprocket to be connected to a first pedal drive sprocket of the bicycle;a second sprocket to be connected to a second pedal drive sprocket ofthe bicycle, a plurality of pawls arranged radially on the secondsprocket to engage with the drive teeth when the pedal shaft is rotatedin the non-drive direction a predetermined rotation, a plurality of biaselements arranged radially within an interior area of the secondsprocket to bias the plurality of pawls toward the drive teeth, and ashift ring arranged within an interior area of the second sprocket toselectively block engagement of the plurality of pawls with the driveteeth.
 2. A multi-speed transmission for a bicycle, comprising: a driverhaving groove and a plurality of drive teeth; a first sprocket pawlarranged in the groove; a first sprocket engaged with the first sprocketpawl, the first sprocket having a first gear ratio; a second sprockethaving a second gear ratio higher than the first gear ratio; a secondsprocket pawl arranged within the second sprocket to selectivelydrivingly engage one or more of the plurality of drive teeth; and ashift ring to rotate with the first sprocket and extend within aninterior area of the second sprocket, the shift ring including a notchto selectively engage the second sprocket pawl and prevent the secondsprocket pawl from drivingly engaging the one or more of the pluralityof drive teeth.
 3. A multi-speed transmission for a bicycle, comprising:a first sprocket and a second sprocket configured to selectivelytransmit torque to a wheel of a bicycle, a transmitting sprocket of thefirst sprocket and the second sprocket shifted through pedaling in anon-drive direction.